This invention relates to a portable telephone set in which reception of an incoming call is announced to a user by means of vibration.
There is known a portable telephone apparatus containing a vibrator for announcing reception of an incoming call by vibrating an apparatus body of the telephone apparatus instead of ringing a call bell. Admittedly, such a call reception announcing function is extremely effective during a call standby state while a user is attending a conference or on board a train. It is essential, however, to carry the telephone apparatus in contact with a user's body all the time.
Although the portable telephone apparatus has become more and more compact, the telephone apparatus is still too large to be carried in contact with the user's body all the time. Also in view of the operability, a restriction is imposed on reduction in size of the telephone apparatus. As a consequence, the telephone apparatus is often carried in a bag or the like. Thus, the call reception announcing function via vibration has not effectively been utilized.
Recently, there is known another technique utilizing a wireless vibration unit which includes a vibrator which separates from a telephone apparatus in the manner known in Japanese Patent Prepublication (Kokai or Publication of Unexamined Patent Application) No. 283852/1991 by Sakurai et al. and in Japanese Patent Prepublication (Kokai or Publication of Unexamined Patent Application) No. 175533/1988 by Murakami. When an incoming call is received in the telephone apparatus, reception is informed to the wireless vibration unit through a wireless path. In response, the vibration unit is made to vibrate to thereby announce reception of the incoming call to a user.
In the above-mentioned technique, however, the wireless vibration unit carries out no more than announcement of reception of the incoming call in the portable telephone apparatus. Sometimes, the user may want to hold the incoming call in dependence upon a caller. For this purpose, the user must take the portable telephone apparatus from his bag, identify the caller, judge whether or not the incoming call is to be put in a holding mode, carry out a holding operation, and transmit to the caller a message, for example, that the user is currently unable to answer. Thus, it takes a long time to respond. In particular, when the user can not freely move, for example, in an overcrowded train or when the portable telephone apparatus is out of reach of the user, the operability is extremely poor.